Dynamically self-adjusting magnetometer

ABSTRACT

A dynamically self-adjusting magnetometer is disclosed. In one embodiment, a first sample module periodically generates an electronic signal related to at least one magnetic field characteristic of a monitored environment. A second sample module periodically generates an electronic signal related to at least one magnetic field characteristic of a monitored environment. A summing module sums the absolute value of the electronic signal from the first sample module and the electronic signal from the second sample module. A delta comparator module receives the electronic signals from each of the first sample module, the second sample module and the summing module and compares each of the electronic signals with a previously received set of electronic signals to establish a change, wherein an output is generated if the change is greater than or equal to a threshold.

CROSS REFERENCE TO RELATED APPLICATIONS

The present patent application is a continuation of U.S. patentapplication Ser. No. 12/961,302, filed Dec. 6, 2010, entitled“Dynamically Self-Adjusting Magnetometer,” by Cory J. Stephansonassigned to the assignee of the present application and incorporated inits entirety herein.

TECHNICAL FIELD

The field of the present invention relates to a dynamicallyself-adjusting magnetometer.

BACKGROUND

Presently, magnetometers are utilized in numerous environments and fornumerous purposes including, safety, defense, detection, environmentmonitoring and the like.

In addition, magnetometers are sophisticated in operation, calibrationand even maintenance. As such, training personnel in the operation ofmagnetometers including application, the proper methodology of use,calibration and repair is a significant investment in time, training andcost. Moreover, if the magnetometers is miss-calibrated, improperlyinstalled, incorrectly located, or the like, detection capabilities ofthe magnetometers can become significantly reduced.

For example, an out of calibration, miss-calibrated or improperlylocated magnetometers can result in improper detection of ferrous metalsin an environment. This can results in a reduced sensitivity of themagnetometer that may remain unknown to the user.

A second problem with an out of calibration, miss-calibrated orimproperly located magnetometer is that once the error is realized, thearea monitored by the magnetometer must either be closed to access orelse a significant reduction in traffic flow is implemented aspreviously automated tasks are now performed by operators utilizinghandheld devices, or the like. Thus, if a user was unsure that thesensor was not operating within calibration and specificationcharacteristics, numerous liability issues would prompt the user to shutdown the system for inspection and/or repair.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

A dynamically self-adjusting magnetometer is disclosed. In oneembodiment, a first sample module periodically generates an electronicsignal related to at least one magnetic field characteristic of amonitored environment. A second sample module periodically generates anelectronic signal related to at least one magnetic field characteristicof a monitored environment. A summing module sums the absolute value ofthe electronic signal from the first sample module and the electronicsignal from the second sample module. A delta comparator module receivesthe electronic signals from each of the first sample module, the secondsample module and the summing module and compares each of the electronicsignals with a previously received set of electronic signals toestablish a change, wherein an output is generated if the change isgreater than or equal to a threshold.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one embodiment for monitoring a magneticfield in an environment is shown in accordance with one embodiment ofthe present technology.

FIG. 2 is a block diagram of a dynamically self-adjusting sensor shownin accordance with one embodiment of the present technology.

FIG. 3 is a flowchart of an exemplary method for monitoring anenvironment with a dynamically adjustable sensor in accordance with oneembodiment of the present technology.

FIG. 4 is a plurality of graphs 410-430 illustrating one embodiment formonitoring an environment with a dynamically adjustable sensor inaccordance with one embodiment of the present technology.

FIG. 5 is a plurality of graphs 510-540 illustrating another embodimentfor monitoring an environment with a dynamically adjustable sensor inaccordance with one embodiment of the present technology.

FIG. 6 is a block diagram of an exemplary computer system in accordancewith one embodiment of the present technology.

FIG. 7 is a block diagram of a self-adjusting magnetic field monitorshown in accordance with one embodiment of the present technology.

FIGS. 8A-8C are block diagrams of different sample module sensor elementorientations shown in accordance with one embodiment of the presenttechnology.

FIG. 9 is a flowchart of an exemplary method for monitoring anenvironment with a dynamically adjustable magnetometer in accordancewith one embodiment of the present technology

The drawings referred to in this description should be understood as notbeing drawn to scale except if specifically noted.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the presenttechnology, examples of which are illustrated in the accompanyingdrawings. While the technology will be described in conjunction withvarious embodiments, it will be understood that they are not intended tolimit the present technology to these embodiments. On the contrary, thepresented technology is intended to cover alternatives, modificationsand equivalents, which may be included within the spirit and scope thevarious embodiments as defined by the appended claims.

Furthermore, in the following detailed description, numerous specificdetails are set forth in order to provide a thorough understanding ofthe present technology. However, the present technology may be practicedwithout these specific details. In other instances, well known methods,procedures, components, and circuits have not been described in detailas not to unnecessarily obscure aspects of the present embodiments.

Overview

A dynamically self-adjusting magnetometer is described. In oneembodiment, the dynamically self-adjusting magnetometer is well suitedto stand-alone operation as well as integration with legacy/futuretechnology.

In general, dynamically self-adjusting refers to the sensor's ability tocalibrate for change in environmental monitored characteristics. Inother words, the capability to adjust to changes in monitored conditionswithout requiring manual recalibration of the sensor, disconnection ofthe sensor or repeated false warnings from the sensor. Thus, the dynamicself-adjusting characteristics allow the dynamically self-adjustingmagnetometer to adjust over time to changes in the environments magneticfield.

Moreover, these changes may be specific to the thing being monitored ormay be generic to the environment around whatever is being monitored.

The following discussion includes an overview of environments that maybe monitored, a general description of a self-adjusting sensor and thena specific discussion of the dynamically self-adjusting magnetometer.

Monitored Environment

With reference to FIG. 1, a block diagram 100 of one embodiment formonitoring an environment is shown. In one embodiment, FIG. 1 includes amonitored environment 110, a dynamically self-adjusting sensor 260 and apossible event 250.

In general, monitored environment 110 is a localized area or portion ofan environment, similar to an ecosystem. For example, monitoredenvironment 110 may be an outdoor area, an indoor area, or a combinationthereof. For example, monitored environment 110 could be a building, aroom, a piece of machinery, a pipeline, a yard, a pool, or the like thata user would want monitored. Additionally, part or all of monitoredenvironment 110 may be dry, partially or completely submerged, partiallyor completely buried, and the like.

Usually, the magnetic field of monitored environment 110 will have acertain baseline for any given period of time. However, it is notuncommon for the baseline of the magnetic field of a monitoredenvironment 110 to change over time. Generally, baseline changes in themagnetic field of a monitored environment 110 can be changes that occurover a longer period of time than a possible event change. For example,temperature changes, weather changes, solar activity and the like.

Dynamically self-adjusting sensor 260 monitors monitored environment 110to recognize an event. When dynamically self-adjusting sensor 260identifies a change in monitored environment 110 due to an event,possible event 250 is generated. In one embodiment, dynamicallyself-adjusting sensor 260 utilizes a relative change methodology insteadof explicit field strength values of monitored environment 110.

In one embodiment, self-adjusting sensor 260 is powered by means of anelectrical power source. This electrical power source may comprise aninternal power source, such as a system battery, or an external powersource, such as a transmission line that delivers alternating currentand that may be accessed through an electrical wall socket. Thedescription of a number of power sources is provided for purposes ofclarity; however, the possible power sources may be other electricaltypes, chemical based, solar based or the like. Thus, the technology iswell suited to alternate powering methods in accordance with the presentinvention. Further, the sensor described herein may be small andportable, e.g., reduced power requirements possibly having a shorterrange; larger vehicle deployed, e.g., increased power requirements,thereby increasing the range; or may be hard mounted, such as on or in abuilding or other structure. In one embodiment, dynamicallyself-adjusting sensor 260 may be selectively powered up and selectivelypowered-down to extend battery life.

Generic Dynamically Self-Adjusting Sensor

With reference now to FIG. 2, a block diagram 200 of a self-adjustingsensor 260 is shown in accordance with one embodiment. In oneembodiment, dynamically self-adjusting sensor 260 includes a samplemodule 220, delta comparator module 230, and window module 240.

As stated herein, self-adjusting sensor 260 may be, but is not limitedto, an optical sensor, a magnetic sensor, an acoustic sensor, and thelike.

In one embodiment, sample module 220 samples monitored environment 110periodically at a pre-defined rate of time and generates a signal 130for each sampling period. In one embodiment, signal 130 may be generatedat a consistent interval. For example, sample module 220 may generatesignal 130 every few milliseconds, few minutes, few seconds, few hoursor the like. By adjusting the signal interval for sample module 220,both sensitivity and range of dynamically self-adjusting sensor 260 maybe adjusted.

For example, sample module 220 may use a 1 MHz crystal to establish ananosecond sample rate. In one embodiment, sample module 220 outputs asignal 130 to delta comparator module 230. In addition, sample module220 also outputs a signal 130 to window module 240 and delta comparatormodule 230.

Referring still to FIG. 2, in one embodiment, window module 240 providesan average signal 145 over a pre-defined number of signals. The averagesignal 145 is provided to delta comparator module 230 and is utilized bydelta comparator module 230 to detect changes in monitored environment110.

In one embodiment, delta comparator module 230 receives a signal 130from sample module 220 at given intervals and compares the signals. Forexample, after delta comparator module 230 receives at least a secondsignal, delta comparator module 230 will compare the two signals andgenerate a delta or difference between the two signals, as shown anddescribed in more detail in FIGS. 4-5 herein. Thus, since in oneembodiment, delta comparator module 230 performs a comparison betweenthe most recent signal and the next most recent signal 440, adynamically self-adjusted baseline for the particular monitoredenvironment 110 is maintained. Further, the delta value generated bydelta comparator module 230 may be a relative value. As such, anexplicit value for the signal 130 is not required. When the resultantdifference between compared signals is greater than or equal to apre-defined difference threshold, delta comparator module 230 provides apossible event 250 output.

With respect to average signal 145, in one embodiment, delta comparatormodule 230 receives average signal 145 from window module 240 andcompares average signal 145 with a previous average signal 145, signal130, or the like. For example, after delta comparator module 230receives at least a second average signal 145, delta comparator module230 will compare the two average signals 145 and generate a delta ordifference between the two average signals 145, as shown and describedin more detail in FIGS. 4-5 herein. In another embodiment, after deltacomparator module 230 receives an average signal 145, delta comparatormodule 230 may compare the average signal 145 with a signal 130 andgenerate a delta or difference between the average signal 145 and thesignal 130. Again, since similar signals are being compared and it isthe change or difference that is utilized, the delta value generated bydelta comparator module 230 may be a relative value. As such, anexplicit value for signal 130 or average signal 145 is not required.When the resultant delta is greater than or equal to a pre-defineddifference threshold, delta comparator module 230 outputs a tangible,concrete possible event 250. Examples of an output of possible event 250include, but are not limited to, a printout, a visual and/or audiosignal, an output to a graphical user interface (GUI), or the like.

Although, in one embodiment, neither signal 130 nor average signal 145need include a specific or quantified value for monitored environment110 as long as sample module 220 provides a consistent representation ofmonitored environment 110 in signal 130. However, in another embodiment,signal 130 and/or average signal 145 may include a specified valuerelated to monitored environment 110.

In one embodiment, delta comparator module 230 may monitor a pluralityof average signals 145 over time to detect changes in monitoredenvironment 110 over time. In yet another embodiment, the functionsdescribed herein as being performed by a single delta comparator module230 may be performed by more than one delta comparator module 230 or maybe performed by the same device that performs the operations of samplemodule 220 and/or window module 240. However, for purposes of clarity,block comparator 230 is shown as a single module and is described hereinas separate from sample module 220 and window module 240.

Operation

With reference now to FIG. 3, a flowchart 300 of one method formonitoring an environment with a dynamically self-adjusting sensor 260is shown in accordance with one embodiment. For clarity in the followingdescription, graphs 410-430 of FIG. 4 and graphs 510-540 of FIG. 5 areutilized in conjunction with Flowchart 300 to illustrate a number of theplurality of possible embodiments. At graph 410 of FIGS. 4 and 510 ofFIG. 5 a characteristic of monitored environment 110 is shown over timeperiod A-n. The characteristic may be an acoustic characteristic, visualcharacteristic, infrared characteristic, or the like.

In general, graph 410 is an example of at least one characteristic ofmonitored environment 110 as occurring over a time A-n. In the followingexamples, A-n are described as sample times. In other words, in oneembodiment described herein, during each of time A-n sample module 220generates a signal 130. As is apparent in graph 410, a small changeoccurs between times A-D and then a large change occurs between timesE-G with a peak at time F. At time n, the characteristics of monitoredenvironment 110 appear to return to the level prior to the spike at F.Thus, graph 410 may be an example of an event that showed up and thenwent away. The event could be a single event, or graph 410 may representa single snippet of a repetitive event.

In one embodiment, graph 510 is an example of at least onecharacteristic of monitored environment 110 as occurring over a timeA-n. In the following examples, A-n are described as sample times. Inother words, in one embodiment described herein, during each of time A-nsample module 220 generates a signal 130. As is apparent in graph 510,little change occurs between times A-B and then a large change occursbetween times C-D with a peak at time E that results in a leveling offof the characteristic at times E-n. At time n, the characteristics ofmonitored environment 110 appear to be stable at the new level. Thus,graph 510 may be an example of an event that showed up and thenremained. Again, in one embodiment, the event could be a single event,or graph 510 may represent a single snippet of a repetitive event.

At 302 of FIG. 3, one embodiment repeatedly generates a signal 130representing at least one characteristic of monitored environment 110.In one embodiment, signal 130 is generated by sample module 220 of FIG.2.

With reference now to 304 of FIG. 3 as well as graph 420 of FIG. 4 and520 of FIG. 5, one embodiment repeatedly calculates a delta changebetween a latest generated electronic signal and the prior electronicsignal. In other words, delta comparator module 230 receives signal 130at given intervals from sample module 220 and compares the new signalwith a previous signal. For example, after delta comparator module 230receives at least a second signal, delta comparator module 230 willcompare the two signals and generate a delta or difference between thetwo signals, as shown in graphs 420 and 520. Thus, since in oneembodiment, delta comparator module 230 performs a comparison betweenthe most recent signal and the next most recent signal, a dynamicallyself-adjusted baseline for the particular monitored environment 110 ismaintained. Further, the delta value generated by delta comparatormodule 230 may be a relative value. As such, an explicit value for thesignal 130 is not required.

For example, at graph 420 the change between A and B (AB) samples isminimal. Similarly, the difference between BC and CD are also minimalHowever, the change at sample time E and the spike at sample time Fclearly show up on graph 420 at DE and DF. Further, at FG the end of thespike is also recognized while at Gn the spike appears to be gone and abaseline characteristic for monitored environment 110 appears to havereturned.

In another example, at graph 520 the change between A and B (AB) samplesis minimal. Similarly, the difference between BC is also minimal.However, the change at sample time C and sample time D are clearly shownon graph 520 at BC and CD. At DE the change in monitored environment 110appears to stabilize and the characteristic for EF, FG and Gn show thelack of change in measured characteristics. Moreover, it is also notedthat while the change may be provided in a positive and negative aspectsuch as shown in graph 420, absolute values for the differences may beused as shown in graph 520.

Referring now to 306 of FIG. 3, when the resultant difference betweenmonitored environment 110 signals 130 is greater than or equal to apre-defined difference threshold, dynamically self-adjusting sensor 260provides a possible event 250 output. For example, at graph 420 thethreshold value is shown as 425 and possible event 250 is output whenthe threshold is passed as illustrated at 423. Similarly, at graph 520the threshold value is shown as 525 and possible event 250 is outputwhen the threshold is passed as illustrated at 523.

With reference now to 308 of FIG. 3, one embodiment repeatedly generatesa floating average for at least two of the latest generated electronicsignals 130. For example, delta comparator module 230 may averagesignals 130 over a group of three sample time periods to generateaverage signal 145. In another embodiment, delta comparator module 230may average received signals 130 over a 5 minute, 20 minute, 1 hour, 2hour, 6 hour, 12 hour, 24 hour, etc. time period before generatingaverage signal 145. In one embodiment, the length of time represented byaverage signal 145 may be directly related to the sensitivity and/orrange of dynamically self-adjusting sensor 260.

With reference now to 310 of FIG. 3 as well as graph 430 of FIGS. 4 and530 and 540 of FIG. 5, one embodiment repeatedly calculates an averagedelta change between the floating average signal 145 for at least two ofthe latest generated electronic signals 130 and the previous averagesignal 145. In one embodiment, floating average signal 145 refers to themethodology of averaging the signals 130. For example, if the floatingaverage signal was based on the average of three signals, then the firstaverage would be the average of signal A+signal B+signal C. However, thenext floating average signal may be the average of signal B+SignalC+Signal D. Thus, although in some embodiments herein, for purposes ofclarity, the averaging is per set of signals, the present technology iswell suited to floating averages as well as block averages.

For example, as shown in graph 430 and 530, in one embodiment, deltacomparator module 230 looks at the difference or change between averagesignal 145 A′ and A′B′. In one embodiment, as shown in 430 thesensitivity of dynamically self-adjusting sensor 260 is not affected bythe direction of a change in strength of monitored environment 110. Inother words, the resultant change may be an absolute value of the change(e.g., as shown in 430). In another embodiment, the resultant change maymaintain its direction of change characteristic such as shown in 530 ofFIG. 5.

By utilizing a difference comparison (e.g., the difference between atleast two signals 130, at least two average signals 145, and/or one ormore signals 130 and one or more average signal 145), changes that occurin monitored environment 110 can be normalized to provide sensitivityfor dynamically self-adjusting sensor 260. For example, if monitoredenvironment 110 varies naturally over time, such as can occur duringchanges in the daily temperature, other machine noise, or the like,because the relative change is evaluated, monitored environment 110variations may prompt an initial possible event 250, however if theevent remains or becomes periodic, dynamically self-adjusting sensor 260will dynamically adjust as shown in A′B′ and B′n′ of 430. In so doing,dynamically self-adjusting sensor 260 can be set to and will remain at aconsistent and very high level of sensitivity. In one embodiment, theoperational sensitivity of dynamically self-adjusting sensor 260 may beless than or equal to the natural variations in the environment'smonitored environment 110.

When comparing graphs 420 and 430, it is clear that having a differingwindow size can affect the reaching of the threshold value. For example,although they represent the same monitored environment 110characteristics. While the threshold 425 of graph 420 is breached at 423causing a possible event 250, the threshold 435 of graph 430 is notbreached. Thus, it is clear that sensitivity and false warnings may bedealt with by adjusting the window size of average signal 145. Further,although only one average signal 145 graph is shown at 430 (and only 2are shown at 530 and 540), the present technology is well suited tohaving a plurality of window sizes. Further, the present technology iswell suited to having a plurality of window sizes operating at the sametime to obtain numerous levels of sensitivity.

In other words, the utilization of window module 240 as well as samplemodule 220 allows dynamically self-adjusting sensor 260 to maintainnumerous levels of sensitivity to changes in monitored environment 110at the same time. Thus, in one embodiment, by utilizing both samplemodule 220 and one or more window module 240, dynamically self-adjustingsensor 260 can have both a high level of sensitivity as well as a largefield of range.

Referring now to 312 of FIG. 3, one embodiment generates a possibleevent 250 output when a difference in the comparing is greater than athreshold. For example, possible event 250 at 533 of graph 530 andpossible event 250 at 543 of graph 540. In one embodiment, possibleevent 250 may be an audible mechanical and/or visual alarm configured tobe heard by a human being. In an alternative embodiment, possible event250 may be sent via a communication network to automatically notifydesignated personnel when an event is detected.

In another embodiment, possible event 250 may be received by anotherdevice that will carry out a follow-on task. For example, possible event250 could provide a turn-on signal for one or more lights, such a lightlocated in the vicinity of the detected event. Additionally, possibleevent 250 could include a signal to generate a notification of thedetected event to a remote location. In one embodiment, possible event250 may initiate an automatic action.

In one embodiment, dynamically self-adjusting sensor 260 wired orwirelessly transmits possible event 250 to a remote communicationsdevice by implementing a communication technology selected from a groupof communication technologies consisting of AM, FM, multi-master serialsingle-ended computer bus such as Inter-Integrated Circuit (I²C), PCM,GPS, RS232, RS485, USB, firewire, infrared and fiber optic communicationtechnologies, and the like. The description of a number of communicationtechnologies is provided herein for purposes of clarity; however, thetechnology is well suited to alternate communication methods inaccordance with the present invention.

Moreover, dynamically self-adjusting sensor 260 is capable of operationin both an attended state and an unattended state. For example,dynamically self-adjusting sensor 260 is well suited to be placed in anenvironment that is constantly supervised, such as in a building, aroundmachinery or the like. In another embodiment, dynamically self-adjustingsensor 260 is able to be “dropped” into an area to act as a standaloneenvironment monitor. For example, dynamically self-adjusting sensor 260may be placed in a location such as a closed hallway, off-limits area,or other environment that may be secluded or dangerous for humanmonitoring, and the like. In one embodiment, during operation in anunmanned operating environment, possible event 250 from dynamicallyself-adjusting sensor 260 may be communicated to a remote site.

Dynamically self-adjusting sensor 260 may also be expanded to includedata storage for various purposes. For instance, in an embodiment,signal 130, average signal 145 and/or information generated by samplemodule 220, window module 240 and delta comparator module 230 may bestored in a storage unit such that the data may be subsequentlyretrieved and further processed. For example, a hard disk drive (HDD) orrandom access memory (RAM) is used to electronically store the data bymeans of arrays of electronic capacitors that are configured to acquirean electronic charge, wherein the charging of the capacitor arrayscorresponds to a digital representation of the acquired data. However,it is understood that the aforementioned examples are merely exemplaryof different storage units that may be implemented pursuant to variousembodiments of the present technology. Other suitable storage units mayalso be utilized to store data such that it may be later accessed andprocessed. For instance, a portable flash drive may be used to storedata, and the flash drive could be physically transported from a firstcomputing system to a second computing system, wherein both computingsystems are capable of accessing data stored on the drive.

Example Computing System

With reference now to FIG. 6, portions of the technology may be composedof computer-readable and computer-executable instructions that reside,for example, on computer-usable media of a computer system. FIG. 6illustrates an example of a computer system 600 that can be used inaccordance with embodiments of the present technology. However, it isappreciated that systems and methods described herein can operate on orwithin a number of different computer systems including general purposenetworked computer systems, embedded computer systems, routers,switches, server devices, client devices, various intermediatedevices/nodes, standalone computer systems, and the like. For example,as shown in FIG. 6, computer system 600 is well adapted to havingperipheral computer readable media 602 such as, for example, a floppydisk, a compact disc, flash drive, back-up drive, tape drive, and thelike coupled thereto.

System 600 of FIG. 6 includes an address/data bus 604 for communicatinginformation, and a processor 606A coupled to bus 604 for processinginformation and instructions. As depicted in FIG. 6, system 600 is alsowell suited to a multiprocessor environment in which a plurality ofprocessors 606A, 606B, and 606C are present. Conversely, system 600 isalso well suited to having a single processor such as, for example,processor 606A. Processors 606A, 606B, and 606C may be any of varioustypes of microprocessors. System 600 also includes data storage featuressuch as a computer usable volatile memory 608, e.g. random access memory(RAM) (e.g., static RAM, dynamic, RAM, etc.) coupled to bus 604 forstoring information and instructions for processors 606A, 606B, and606C. System 600 also includes computer usable non-volatile memory 610,e.g. read only memory (ROM) (e.g., read only memory, programmable ROM,flash memory, EPROM, EEPROM, etc.), coupled to bus 604 for storingstatic information and instructions for processors 606A, 606B, and 606C.Also present in system 600 is a data storage unit 612 (e.g., a magneticor optical disk and disk drive, solid state drive (SSD), etc.) coupledto bus 604 for storing information and instructions.

System 600 also includes an alphanumeric input device 614 includingalphanumeric and function keys coupled to bus 604 for communicatinginformation and command selections to processor 606A or processors 606A,606B, and 606C. System 600 also includes a cursor control device 616coupled to bus 604 for communicating user input information and commandselections to processor 606A or processors 606B, and 606C. System 600 ofthe present embodiment also includes a display device 618 coupled to bus604 for displaying information. In another example, alphanumeric inputdevice 614 and/or cursor control device 616 may be integrated withdisplay device 618, such as for example, in the form of a capacitivescreen or touch screen display device 618.

Referring still to FIG. 6, optional display device 618 of FIG. 6 may bea liquid crystal device, cathode ray tube, plasma display device orother display device suitable for creating graphic images andalphanumeric characters recognizable to a user. Cursor control device616 allows the computer user to dynamically signal the movement of avisible symbol (cursor) on a display screen of display device 618. Manyimplementations of cursor control device 616 are known in the artincluding a trackball, mouse, touch pad, joystick, capacitive screen ondisplay device 618, special keys on alpha-numeric input device 614capable of signaling movement of a given direction or manner ofdisplacement, and the like. Alternatively, it will be appreciated that acursor can be directed and/or activated via input from alpha-numericinput device 614 using special keys and key sequence commands. System600 is also well suited to having a cursor directed by other means suchas, for example, voice commands, touch recognition, visual recognitionand the like. System 600 also includes an I/O device 620 for couplingsystem 600 with external entities. For example, in one embodiment, I/Odevice 620 enables wired or wireless communications between system 600and an external network such as, but not limited to, the Internet.

Referring still to FIG. 6, various other components are depicted forsystem 600. Specifically, when present, an operating system 622,applications 624, modules 626, and data 628 are shown as typicallyresiding in one or some combination of computer usable volatile memory608, e.g. random access memory (RAM), and data storage unit 612.

Examples of well known computing systems, environments, andconfigurations that may be suitable for use with the present technologyinclude, but are not limited to, personal computers, server computers,hand-held or laptop devices, multiprocessor systems,microprocessor-based systems, set-top boxes, programmable consumerelectronics, network PCs, minicomputers, mainframe computers,distributed computing environments that include any of the above systemsor devices, and the like.

It should be further understood that the examples and embodimentspertaining to the systems and methods disclosed herein are not meant tolimit the possible implementations of the present technology. Further,although the subject matter has been described in a language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

Magnetometer

With reference now to FIG. 7, a block diagram 700 of a self-adjustingmagnetic field monitor 760 is shown in accordance with one embodiment ofthe present technology. In one embodiment, self-adjusting magnetic fieldmonitor 760 includes a sample module 720 a, sample module 720 n, summingmodule 727, delta comparator module 730, and window module 740.

The following description provides a number of embodiments for utilizinga self-adjusting magnetic field monitor 760. For purposes of clarity, inthe following description aspects of the self-adjusting magnetic fieldmonitor 760 that may be similar in function to that of self-adjustingsensor 260 will not be described in detail, but will refer to theoperational characteristics previously described herein. However, itshould be understood that the referral to the previous description isnot provided as a limitation to that which has been previouslydescribed, but is instead provided as one example of the operation of asimilarly functioning portion. Thus, aspects of the technology are wellsuited to variations, additions, permutations or the like.

In one embodiment, sample module 720 a and sample module 720 n samplemonitored environment 110 periodically at a pre-defined rate of time andgenerate a corresponding signal 725 a and 725 n, respectively, for eachsampling period. For example, sample modules 720 a and 720 n maygenerate new signals 725 a and 725 n every few milliseconds, fewminutes, few seconds, few hours or the like. By adjusting the signalinterval for sample module 720 a and sample module 720 n, bothsensitivity and range of self-adjusting magnetic field monitor 760 maybe adjusted. Although two sample modules are shown, the presenttechnology is well suited to any number of sample modules. Moreover, asdescribed in further detail herein, by adding additional sample modules,or channels, further levels of granularity and sensitivity can beobtained.

In one embodiment, the signals 725 a and 725 n generated by samplemodule 720 a and sample module 720 n, respectively, are oscillatingsignals at a frequency that is proportional to the ambient magneticfield of monitored environment 110. For example, the oscillation may bepulse shaped. In one embodiment, for each sample period, the signals 725a and 725 n represent the frequency of the oscillation for the sampleperiod. In another embodiment, signals 725 a and 725 n are the absolutevalue representing the frequency of the oscillation for the sampleperiod.

In one embodiment, sample module 720 a and sample module 720 n outputsignals 725 a and 725 n, respectively to summing module 727, windowmodule 740 and delta comparator module 730. In one embodiment, summingmodule 727 is utilized to sum the output of two or more sample modules.In so doing, the sensitivity of the self-adjusting magnetic fieldmonitor 760 may be multiplied by the number of sample modules beingutilized. In one embodiment output 729 from summing module 727 isprovided to both window module 740 and also to delta comparator module730. For example, in diagram 700, output 745 from window module 740 mayinclude output 729.

Referring still to FIG. 7, in one embodiment, window module 740 providesan average signal 745 over a pre-defined number of signals 725 a and 725n. The average signal 745 is provided to delta comparator module 730 andis utilized by delta comparator module 730 to detect changes inmonitored environment 110. In one embodiment, the average signal 745 mayinclude the average signal for signals 725 a, the average signal forsignals 725 n and the average signals for signal 729.

In one embodiment, delta comparator module 730 receives signal 725 a and725 n from sample module 720 a and sample module 720 n at givenintervals. Delta comparator module compares each new signal with aprevious signal. For example, looking only at sample module 720 a, afterdelta comparator module 730 receives at least a second signal, deltacomparator module 730 will compare the two signals and generate a deltaor difference between the two signals, as shown and described in moredetail in FIGS. 4-5 herein. Thus, since in one embodiment, deltacomparator module 730 performs a comparison between the most recentsignal and the next most recent signal, a dynamically self-adjustedbaseline for the monitored environment 110 is maintained. Further, thedelta value generated by delta comparator module 730 may be a relativevalue. As such, an explicit value for the signal 725 a is not required.When the resultant difference between compared signals is greater thanor equal to a pre-defined difference threshold, delta comparator module730 provides a possible event 750 output.

With respect to average signal 745, in one embodiment, delta comparatormodule 730 receives average signal 745 from window module 740 andcompares average signal 745 with a previous average signal 745. Asstated herein, average signal 745 may include an average for signals 725a, 725 n and 729. For example, after delta comparator module 730receives at least a second average signal 745, delta comparator module730 will compare the two average signals 745 and generate a delta ordifference between the two average signals 745, as shown and describedin more detail in FIGS. 4-5 herein. Again, since average signal 745 iscompared with another average signal 745 and the change is utilized, thedelta value generated by delta comparator module 730 may be a relativevalue. As such, an explicit value for average signal 745 is notrequired. In one embodiment, signals 725 a and 725 n may be compared toeach other, to other signals generated by the sensor, or to one or moreof the average signals 745. In addition, the value for average signal745 may be tailored for different purposes by using differentconstituent signals to compose the average. When the resultant delta isgreater than or equal to a pre-defined difference threshold, deltacomparator module 730 outputs a tangible, concrete possible event 750.Examples of an output of possible event 750 include, but are not limitedto, a printout, a visual and/or audio signal, an output to a graphicaluser interface (GUI), or the like.

As stated herein, in one embodiment, signals 725 a, 725 n, 729 and 745do not need to include a specific or quantified value for monitoredenvironment 110 as long as sample module 720 a and sample module 720 nprovide a consistent representation of monitored environment 110.However, in another embodiment, signals 725 a, 725 n, 729 and/or averagesignal 745 may include a specified value related to the magnetic fieldof monitored environment 110.

In one embodiment, delta comparator module 730 may monitor a pluralityof average signals 745 over time to detect changes in monitoredenvironment 110 over time. In yet another embodiment, the functionsdescribed herein as being performed by a single delta comparator module730 may be performed by more than one delta comparator module 730 or maybe performed by the same device that performs the operations of samplemodule 720 and/or window module 740. However, for purposes of clarity,delta comparator module 730 is shown as a single module and is describedherein as separate from sample module 720 and window module 740.

With reference now to FIGS. 8A-8C, block diagrams 800, 850 and 875 areprovided to illustrate three of the plurality of different sample modulesensor element orientations in accordance with one embodiment of thepresent technology. In the following discussion, sensor element 810 a isutilized by sample module 720 a and sensor element 810 n is utilized bysample module 720 n.

In general, the relative sensitivity to a given magnetic field change isa direct function of the orientation of the moving ferrous object to thesensor element. That is, with a given radial polarity, the sensor isvery sensitive to the event on one axis and not as sensitive on theorthogonal axis. Basically, the individual sensor detection pattern fora given polarity follows a dual-law of cosines function.

FIG. 8A illustrates a first arrangement that includes sensor element 810a perpendicular to sensor element 810 n. In one embodiment, by providingperpendicular orientation of the sensor elements, self-adjustingmagnetic field monitor 760 will be sensitive in a circular pattern,regardless of the orientation or polarity of the event being detected.

FIGS. 8B and 8C illustrate a second and third parallel sensor element810 a and 810 n arrangement. In contrast to the operation of theperpendicular orientation of the sensor elements, the parallelarrangement will provide a higher sensitivity in a first direction and alower sensitivity in an orthogonal direction. In other words, byarranging the sensor elements in parallel, sensitivity and/or range ofself-adjusting magnetic field monitor 760 may be multiplied for an eventthat occurs in a given direction with respect to the sensor orientation.However, it should be appreciated that the number of sample modulesutilized by self-adjusting magnetic field monitor 760 may be more thantwo and as such a combination of sensor element orientations may beutilized. For example, a three sensor element configuration may includea combination of configuration 800 and configuration 875, or the like.

With reference now to FIG. 9, a flowchart of an exemplary method formonitoring an environment with a dynamically adjustable magnetometer isshown in accordance with one embodiment of the present technology.

At 902 of FIG. 9, one embodiment periodically generates a first channelelectronic signal representing a magnetic field of a monitoredenvironment. For example, as shown in FIG. 7, sample module 720 a maygenerate a new signal 725 a every few milliseconds, few minutes, fewseconds, few hours or the like. By adjusting the signal interval forsample module 720 a, both sensitivity and range of self-adjustingmagnetic field monitor 760 may be adjusted.

In one embodiment, signal 725 a, generated by sample module 720 a, is anoscillating signal at a frequency that is proportional to the ambientmagnetic field of monitored environment 110. For example, theoscillation may be pulse shaped. In one embodiment, for each sampleperiod, the signal 725 a may represent the frequency of the oscillationfor the sample period. In another embodiment, signal 725 a is theabsolute value representing the frequency of the oscillation for thesample period.

At 904 of FIG. 9, one embodiment periodically generates at least asecond channel electronic signal representing the magnetic field of themonitored environment. For example, as shown in FIG. 7, sample module720 n may generate a new signal 725 n every few milliseconds, fewminutes, few seconds, few hours or the like. By adjusting the signalinterval for sample module 720 n, both sensitivity and range ofself-adjusting magnetic field monitor 760 may be adjusted.

In one embodiment, signal 725 n, generated by sample module 720 n, is anoscillating signal at a frequency that is proportional to the ambientmagnetic field of monitored environment 110. For example, theoscillation may be pulse shaped. In one embodiment, for each sampleperiod, the signal 725 n may represent the frequency of the oscillationfor the sample period. In another embodiment, signal 725 n is theabsolute value representing the frequency of the oscillation for thesample period.

Although two sample modules are shown, the present technology is wellsuited to any number of sample modules. Moreover, as described infurther detail herein, by adding additional sample modules, or channels,further levels of granularity and sensitivity can be obtained.

At 906 of FIG. 9, one embodiment calculates a delta change between thetotal oscillation value for a latest period and the total oscillationvalue for the prior period. For example, as shown in FIG. 7, in oneembodiment, delta comparator module 730 receives signal 725 a and 725 nfrom sample module 720 a and sample module 720 n. Delta comparatormodule compares each new signal 725 a and 725 n with a previous signal.For example, looking only at sample module 720 a, after delta comparatormodule 730 receives at least a second signal 725 a, delta comparatormodule 730 will compare the two signals 725 a and generate a delta ordifference between the two signals, as shown and described in moredetail in FIGS. 4-5 herein. In one embodiment, signals 725 a and 725 nmay be compared to each other, to other signals generated by the sensor,or to one or more of the average signals 745. In addition, the value foraverage signal 745 may be tailored for different purposes by usingdifferent constituent signals to compose the average.

At 908 of FIG. 9, one embodiment sums an absolute value of the firstchannel electronic signal and an absolute value of at least a secondchannel electronic signal for each period to generate a total value foreach period. In one embodiment, as shown in FIG. 7, summing module 727is utilized to sum the output of each sample module. In so doing, thesensitivity of the self-adjusting magnetic field monitor 760 may bemultiplied by the number of sample modules being utilized.

Thus, since in one embodiment, delta comparator module 730 performs acomparison between the most recent signal 725 a and the next most recentsignal 725 a, a dynamically self-adjusted baseline for the monitoredenvironment 110 is maintained. Further, since signal 725 a is comparedwith another signal 725 a and the change is utilized, the delta valuegenerated by delta comparator module 730 may be a relative value. Assuch, an explicit value for the signal 725 a is not required. In oneembodiment, signals 725 a and 725 n may be compared to each other, toother signals generated by the sensor, or to one or more of the averagesignals 745. When the resultant difference between compared signals 725a is greater than or equal to a pre-defined difference threshold, deltacomparator module 730 provides a possible event 750 is output. In oneembodiment, delta comparator module 730 may also utilize a matrix filteror stage filter and run the received electronic signals through thefilter more than one time to generate a gain that will result inincreased sensitivity.

At 910 of FIG. 9, one embodiment generates an output if the delta changeis greater than a pre-defined threshold. For example, with respect toFIG. 7, when the resultant delta is greater than or equal to apre-defined difference threshold, delta comparator module 730 outputs atangible, concrete possible event 750. Examples of an output of possibleevent 750 include, but are not limited to, a printout, a visual and/oraudio signal, an output to a graphical user interface (GUI), or thelike.

In one embodiment, magnetic field monitor 760 is capable of operation inboth an attended state and an unattended state. For example, magneticfield monitor 760 is well suited to be placed in an environment that isconstantly supervised, such as a checkpoint, chokepoint, or the like. Inanother embodiment, magnetic field monitor 760 is able to be “dropped”into an area to act as a standalone environment monitor. For example,magnetic field monitor 760 may be placed in a location such as a closedhallway, off-limits area, front yard, driveway, room exit, buildingexit, parking garage, perimeter, and the like. In one embodiment, duringoperation in an unmanned operating environment, possible event 750 frommagnetic field monitor 760 may be communicated to a remote site, mayinitiate an alarm, initiate a lock-down sequence, provide an activationsignal to another device, and the like.

In general, magnetic field monitor 760 may be employed in desert,jungle, riverine, littoral and/or coastal regions. Furthermore, due tothe self-calibrating characteristics, magnetic field monitor 760 is alsocapable of operating under a wide range of physical conditions such as,high humidity, low humidity, extreme temperature ranges, dusty, dirty,sandy and muddy conditions, partially or completely submerged, partiallyor completely buried, and the like. For example, magnetic field monitor760 is capable of operating in environments with one or more significantphysical conditions such as, but not limited to, tropical or arcticenvironments.

Additionally, magnetic field monitor 760 is capable of operation inenvironments having changing physical conditions. That is, therepetitive self-calibrating capabilities of magnetic field monitor 760allow magnetic field monitor 760 to remain viable in a constantlychanging environment such as a desert environment that may have daily orweekly environmental changes (e.g., temperatures that range from at orbelow freezing at night to 40 degrees Celsius midday). In anotherembodiment, magnetic field monitor 760 is also well suited for operationin a controlled environment having little or no harsh physicalconditions, such as an airport terminal, building, parking lot and thelike.

In another embodiment, magnetic field monitor 760 is also very useful inan environment where a walk-through or hand-held metal detector isutilized. Although, as stated herein, magnetic field monitor 760 is wellsuited as a replacement for either or both of the walk-through andhand-held metal detector, due to the distinctly different approach ofmonitoring an environments magnetic field, magnetic field monitor 760 isalso well suited for use in conjunction with a walk-though and/orhand-held metal detector. For example, in many security environmentspeople are formed up in queue to pass through the checkpoint. Inaddition, some checkpoints such as metal-detection checkpoints provide achokepoint with many unscreened people waiting to pass through themetal-detector. The present security checkpoints do not provide securityfor people waiting to pass through. Moreover, in higher stressenvironments security personnel are on lookout for people that appearstressed or people dressed in loose clothing that are approaching thecheckpoint. In some environments, a human evaluation may be utilized bysecurity personnel prior to a suspicious person even entering thescreening queue. For example, a security guard may have to ask someoneto open up the baggy shirt or answer a few questions.

However, magnetic field monitor 760 may be deployed in this samescenario as a means of pre-scanning anyone or anything approaching thecheckpoint. For example, in one embodiment, magnetic field monitor 760may be set to output signal 750 if an event is detected within apre-defined area around the checkpoint. Such a pre-warning would allowanyone at the checkpoint to react to the event with an amount ofstand-off distance. Further, in one embodiment, when used in combinationwith a walk-through metal detector, magnetic field monitor 760 may becalibrated to increase range while sacrificing some sensitivity sincethe walk-through metal detector may be providing the finer level ofsensitivity.

Although a walk-through or hand-held metal detector is utilized in theexample, it is merely as an example of one way magnetic field monitor760 may be incorporated into a previously established screeningscenario. In yet another embodiment, magnetic field monitor 760 may actas both the long range and fine level detector in a similar checkpointwithout requiring any other type of metal detection system.

In one embodiment, by utilizing two or more magnetic field sensors 720,magnetic field monitor 760 is also capable of determining additionalinformation relating to an event, information such as speed, direction,velocity, etc.

What is claimed is:
 1. A computer-implemented method for monitoring anenvironment with a dynamically adjustable magnetometer, said methodcomprising: periodically generating a first channel electronic signalrepresenting a magnetic field of a monitored environment; periodicallygenerating at least a second channel electronic signal representing saidmagnetic field of said monitored environment; calculating a delta changebetween the total value for a first period and the total value for asecond period; summing an absolute value of said first channelelectronic signal and an absolute value of said at least a secondchannel electronic signal over a period to generate a total value for afirst period and the total value for a second period; generating anoutput if said total value is greater than a pre-defined threshold;utilizing an average total value for more than two periods to repeatedlygenerate a second floating average; calculating an average delta changebetween two different period second floating averages; and generatingsaid output if the average delta change is greater than a pre-definedthreshold.
 2. The computer-implemented method of claim 1, wherein saidperiodically generating a first channel electronic signal is performedby a magnetic field sensor selected from the group consisting of: afluxgate sensor, a magneto inductive sensor, a magneto resistive sensor,a Cesium vapor, and a skinning induction-effect sensor.
 3. Thecomputer-implemented method of claim 1 further comprising: utilizing anoscillation frequency over a period of time to periodically generatesaid first channel electronic signal and said second channel electronicsignal.
 4. The computer-implemented method of claim 1 furthercomprising: converting said first channel electronic signal and at leastsaid second channel electronic signal from an analog signal to a digitalsignal.
 5. The computer-implemented method of claim 1 furthercomprising: utilizing the average total value for at least two of thelatest periods to repeatedly generate a floating average; calculating anaverage delta change between a first period floating average and asecond period floating average; and generating said output if theaverage delta change is greater than a pre-defined threshold.
 6. Thecomputer-implemented method of claim 1 wherein the output is selectedfrom the group consisting of: a printout, a visual signal, an audiosignal, and an output to a graphical user interface (GUI). 7.Instructions on a non-transitory computer-usable medium wherein theinstructions when executed cause a computer system to perform a methodfor monitoring an environment with a dynamically adjustable sensor, saidmethod comprising: periodically generating a first channel electronicsignal representing a magnetic field of a monitored environment;periodically generating a first channel average electronic signalrepresenting an average of two or more of said periodically generatedfirst channel electronic signals; calculating a delta change between twoof said electronic signals wherein said two of said electronic signalsutilized when calculating said delta change are selected from the groupconsisting of: a first channel electronic signal from a first period anda first channel electronic signal from a second period, said firstchannel electronic signal from said first period and a first channelaverage electronic signal from a first period, said first channelelectronic signal from said first period and a first channel averageelectronic signal from a second period, and said first channel averageelectronic signal from a first period and a first channel averageelectronic signal from a second period; and generating an output if saiddelta change is greater than or equal to a pre-defined threshold.
 8. Thenon-transitory computer-usable medium of claim 7 further comprising:periodically generating at least a second channel electronic signalrepresenting said magnetic field of said monitored environment;calculating a delta change between the total value for a first periodand the total value for a second different period; summing an absolutevalue of said first channel electronic signal and an absolute value ofsaid at least a second channel electronic signal for each period togenerate a total value for each said period; and generating an output ifsaid delta change is greater than a pre-defined threshold.
 9. Thenon-transitory computer-usable medium of claim 8 further comprising:utilizing the average total oscillation value for at least two periodsto repeatedly generate a floating average; calculating an average deltachange between a first period floating average and a second differentperiod floating average; and generating said output if the average deltachange is greater than a pre-defined threshold.
 10. The non-transitorycomputer-usable medium of claim 9 further comprising: utilizing anaverage total value for more than two periods to repeatedly generate asecond floating average; calculating an average delta change between afirst period second floating average and a second different periodsecond floating average; and generating said output if the average deltachange is greater than a pre-defined threshold.